Lisa Sheffer is the social worker at the Hatch institute who promises to take care of Thomas and help Dominick get him transferred somewhere else. This doesn't work out the way they hope, though.
While Sheffer is very by the book, she has no problem suggesting certain rules for Dominick to break in order to game the system. Unlike most doctors and social workers Dominick has worked with in the past, Sheffer actually cares. Unfortunately, like Dominick, she might care a little too much, and she ends up hurting Thomas more than she helps him.
By circumnavigating the rules, she does get Thomas out, but he ends up killing himself. She feels guilty about it, but everyone eventually gets over it.
Dr. Patel, like Dr. Sheffer, is also a medical professional who actually cares, except in this case she cares much more about Dominick than Thomas. She's pretty much written Thomas off as a lost cause, so she focuses on long therapy sessions with Dominick about his relationship with his family, his "passive-aggressive" (15.12) nature, and the god Shiva, who "represents the reproductive power of destruction" (15.15). What does the mean by that? Maybe she means that by destroying Thomas, Dominick can begin to heal himself, which is exactly what happens.
She also encourages Dominick to stop talking about "The Dominick Birdsey Museum of Injustice and Misery" (34.177), i.e. to quit talking about his stupid pain all the time and do something about it. What does she suggest? Reading his grandfather's memoirs from cover to cover, even when Dominick thinks about burning the whole thing. We guess that kind of destruction wouldn't be rejuvenating at all.